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Back2Basics: Understanding Closure data etc.
Aloha,
I recently purchased TraversePC survey software–they gave an excellent discount for us as a non profit organization. Very helpful folks. Just began to use it. I enter one of simplest lot of the seven lots we have. Entered the Az. and HD per the deed, the program created pretty cool drawing. The software give a summary of closure data–see screenshots. It shows error summary and there are few things that I don’t understand.
1. What is “relative error?” How was this value obtained?
2. Linear error of 0.01 and how this value was obtained?
3. Closing point, why the program list point #1 as correct? Is this because that is where the last point should be for a perfect closure?
4. On the drawing…the label for the curve, T= 95.46′ What does “T” stands for? What portion of the drawing does this distant represent?Thank you as always for the guidance!
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8 Replies
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Relative error is the ratio of error, 588.39/0.011 although the .011 is not carried out to enough digits to get the same result the software posted.
Linear error is the calculated difference between the coordinates of point 1 and point 5
0.0066 north and 0.0088 east, the vector between them being .011 feet.3 – yes
T= tangent, the distance between the PC and the PI
http://www.engineeringcivil.com/circular-curves.htmlJames
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> Relative error is the ratio of error, 588.39/0.011 although the .011 is not carried out to enough digits to get the same result the software posted.
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> Linear error is the calculated difference between the coordinates of point 1 and point 5
> 0.0066 north and 0.0088 east, the vector between them being .011 feet.
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> 3 – yes
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> T= tangent, the distance between the PC and the PI
> http://www.engineeringcivil.com/circular-curves.html
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> JamesAloha, James & Beer Legs:
Thank you for the replies!
I was dividing 588.39/0.011 but didn’t get the same result…with your confirmation I am relieved now. Engineering site url has a lot of educational information.
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By reversing the equation –
588.39/53545 = 0.010988701.011 by the coordinates or .01 as shown on the printout is close enough.
James
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> By reversing the equation –
> 588.39/53545 = 0.010988701
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> .011 by the coordinates or .01 as shown on the printout is close enough.
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> JamesAloha, James: Thanks!:good:
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:good: I had always thought TPC was the hands down coolest survey software that i’d seen. This is from using a VERY EARLY version of that software.
I was wondering how it was that you ran your description in one direction – gauging from the point number increment – but the azimuths run the other direction?
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> :good: I had always thought TPC was the hands down coolest survey software that i’d seen. This is from using a VERY EARLY version of that software.
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> I was wondering how it was that you ran your description in one direction – gauging from the point number increment – but the azimuths run the other direction?Aloha, RJS:
I am very new at this…could it be because I am using South Azimuth? In Hawaii all surveys are done clockwise from true South.Do you still us TPC? I wonder how many surveyors here us TPC?
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Aloha, RJS:
I am very new at this…could it be because I am using South Azimuth? In Hawaii all surveys are done clockwise from true South.Ahhh..I see, the old South Azimuth would answer the question.
Do you still us TPC? I wonder how many surveyors here us TPC?
No, I don’t currently use TPC, and haven’t for many years. Cool choice for software.
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